Hydrophobically modified hydroxyethylcellulose is known from U.S. Pat. No. 4,228,277 to be a clear effective thickener in latex paint compositions and shampoos. Since the time of the initial discovery of these associative thickeners, additional applications have been discovered such as paper coating compositions, etc.
Ceramic greenware can be decorated and coated with a variety of glazes prior to firing. When sanitary ceramic articles are produced, the glaze must meet the same exacting requirements as for decorative ceramic articles. Sinks and toilets must be fired using glazes meeting sanitary requirements and be suitable for extended service.
Cellulose ethers and xanthan gums have been used as thickeners and binders for such sanitary ceramic glazes. Upon firing, these polysaccharides decompose and form the glaze glass and metal oxide deposit on the ceramic article. Varial.RTM. ceramic glaze, for example, is a blend of approximately 20% xanthan gum with 80% sodium polyphosphate, available from Chemische Werk Tubingen of Germany.
A particularly useful sanitary ceramic glaze comprises feldspars, clays, kaolin, quartz metal oxides and frits all together called ceramic raw materials. These ceramic raw materials are suspended in water and stabilized by a mixture of xanthan gum and sodium polyphosphate. Yet even with its advantages and demonstrated utility there were problems of high cost and limited workability. It remained for the present invention to provide a high value in use of sanitary ceramic glaze which could overcome the disadvantages of the prior art.